1. Field of the Invention
THE PRESENT INVENTION relates to an air-bag arrangement, and more particularly relates to an air-bag arrangement in the form of an inflatable curtain.
2. Description of Related Art
It has been proposed to provide an inflatable curtain in a motor vehicle. The inflatable curtain is in the form of an air-bag which is initially mounted and stored, for example, in the roof lining of the vehicle at a position above the door openings at the side of the vehicle. In response to an accident, especially a side impact or roll-over accident, the inflatable curtain inflates and extends downwardly from its mounting position, to extend adjacent the windows in the motor vehicle. The inflatable curtain is positioned between the head of each occupant and the adjacent window, thus providing a degree of protection for the head of the occupant and minimising the risk that the head of the occupant will be thrown out, through the window opening, after the window has broken during the accident.
Inflatable curtains are often formed from air-bags having inflatable regions and uninflatable regions, with the inflatable regions being divided into one or more elongate cells or chambers. Each inflatable region is located at a position where it is most likely that the head of an occupant will strike the inflatable curtain during an accident. It is desirable for each inflatable region to be inflated before the head of an occupant adjacent that inflatable region strikes the inflatable curtain.
It has been found that in many motor vehicles, especially vehicles having multiple rows of seats, an occupant in the rear-most row of seats is positioned, probably due to the presence of a rear wheel mudguard, closer to the centre or axis of the vehicle than a vehicle occupant sitting further towards the front of the vehicle. Thus the head of an occupant towards the front of the vehicle will almost inevitably impact with an inflatable curtain before the head of an occupant of the rear-most row of seats. This applies especially in connection with a vehicle having three rows of seats, but may also apply to some vehicles having two rows of seats.
It is desirable to inflate an inflatable curtain using a minimum quantity of gas to minimize the costs and the weight of the gas generator. Also, it is further desirable for an inflatable curtain to be inflated within a very short period of time, for example, during a time period of approximately 18 mS.